The recent advancement of minimally-invasive surgical procedures has proven to be an advantageous alternative over prior invasive surgical procedures. Advantages gained by minimally-invasive surgical procedures include quicker recovery time as well as a reduction in the length of hospital stays and medical costs.
Generally, minimally invasive surgery involves incising through body walls, for example, viewing and/or operating on the heart, ovaries, uterus, gall bladder, bowels, kidneys, appendix, etc. In one instance of such surgery, a trocar assembly is utilized for creating the incisions through which the endoscopic surgery is performed. The trocar assembly may include a sharp pointed obturator which is used to puncture and penetrate the skin and surrounding tissue to reach the surgical site. The obturator is positioned within a cannula which is generally configured as a sleeve member. The cannula remains in place after the obturator has been removed and provides a path for the insertion of surgical equipment needed for the particular surgical procedure.
Typically, a camera or endoscope is inserted through a cannula thereby enabling the visual inspection and magnification of the body cavity. With the visual assistance of an endoscope and external television monitor, the surgeon can perform diagnostic and therapeutic procedures at the surgical site with the aid of specialized instrumentation, such as, graspers, dissectors, electrocautery devices, and the like which are specifically designed for introduction and manipulation through additional cannulas.
Thus, instead of a large incision (typically 4-12 inches or larger) that cuts through major muscles, patients undergoing endoscopic surgery receive more cosmetically appealing incisions, which are typically between 5 and 10 millimeters in size, or smaller. Recovery is, therefore, much quicker.
In many minimally invasive surgical procedures, including those involved in endoscopic surgery, it is often necessary to suture organs or tissue and thereafter knot the suture material so as to approximate or adjoin tissue pieces. Such procedures may be especially challenging during minimally invasive surgery because of the small openings through which the suturing of the organs or tissues must be accomplished.
In the past, suturing of tissue through endoscopic surgery was achieved through the use of a sharp suture needle attached to an end of a length of suture material. In a typical endoscopic surgical procedure, the surgeon grasps the suture needle with an endoscopic grasping instrument, enabling the suture needle to be introduced into the abdominal body cavity of the patient, via a cannula. Through manipulation of the grasping instrument, the surgeon causes the suture needle to penetrate and pass through tissue, thereby also pulling the suture material therethrough. Unfortunately, using a grasping instrument with a suture needle is time consuming and burdensome due to the difficult maneuvers and manipulations which are required through the small endoscopic openings.
Fortunately, suturing devices for minimally invasive surgery have been developed which obviate the difficult suturing maneuvers which had been previously necessary. For example, U.S. Pat. No. 5,431,666 to Sauer et al; U.S. Pat. No. 5,766,183 to Sauer; U.S. Pat. No. 6,641,592 to Sauer; U.S. Pat. No. 7,211,093 to Sauer et al; U.S. Pat. No. 7,731,727 to Sauer; U.S. Pat. No. 8,398,657 to Sauer; and U.S. Pat. No. 8,926,640 to Sauer et al disclose a variety of useful surgical suturing devices for use with minimally invasive surgery, and those patents are all hereby incorporated by reference in their entirety. Similar devices are also commercially available from LSI Solutions, Inc., of Victor, N.Y., such as, but not limited to the RD180® suturing device. (See, for example, www.lsisolutions.com) Such suturing devices feature, among other things, a needle which may be actuated from a first position, through tissue positioned in a tissue bite area, and into contact with a ferrule at a second position. The ferrule is attached to a suture, and is taught to have an inner diameter which is slightly smaller than the outer diameter of the sharpened ends of the needle which contacts it. Thus, when the sharpened ends of the needle contact (are inserted into) the ferrule, friction holds the ferrule onto the sharpened end. The needle may then be moved back through the tissue to its starting position, pulling the ferrule and its attached suture along with it through the tissue. It is important to have a good fit (not too loose) between the needle tip and ferrule so that the ferrule remains engaged while being pulled through the tissue. It is also important in some embodiments that the ferrule not be attached too tightly to the needle, since some suturing devices can release the ferrule from the needle for the convenience of the operator, or even reset the ferrule (by removing it from the needle and putting it back in a starting position) for one or more additional stitches. In cases where the ferrule will be re-used, it is important that the frictional hold of the ferrule on the needle does not deform or stretch the ferrule to the point where it cannot reliably be used for multiple stitches. To address this, the dimensions of needle tips and inner diameters of ferrules in the prior art have exacting tolerances.
The popularity of these types of minimally invasive suturing devices has led to their growing use in a variety of different surgical procedures. As new suturing devices are developed, they may often benefit from needles of different sizes, shapes, and orientations. Correspondingly, different ferrules are often needed for mating with each new or different type of needle in a surgical suturing device. Not only does this lead to the need for customers to purchase and track different kinds of ferruled sutures for different procedures, it can make it difficult for surgeons to utilize a single suture with multiple suturing devices.
Therefore, there is a need for an improved ferrule which can reliably function with a variety of existing suturing devices for a range of different needle types and dimensions.